Film removal employing a remote plasma source

Abstract

A method and device for removing film from a substrate are provided that take advantage of a remote plasma source to etch away undesired portions of films, such as dielectric films formed on a substrate. To that end, the method includes forming a plasma remotely with respect to the process chamber, from which a flow is created that is directed toward the substrate. The substrate is of a type having opposed major surfaces with a peripheral surface extending therebetween. A film, such as a dielectric film, is disposed on one of the opposed major surfaces and on the peripheral surface. The opposed major surface having the film thereon is shielded from the flow of reactive radicals while the peripheral surface is left exposed. In this fashion, the flow is maintained for a sufficient amount of time to remove film present on the peripheral surface.

What is claimed is:  
     
       1. A method of removing film from a substrate of the type having first and second opposed major surfaces and a peripheral surface positioned therebetween, with said film being present on said first opposed major surface and said peripheral surface, with said substrate being disposed in a process chamber, said method comprising: 
       forming a plasma remotely with respect to said process chamber, said plasma including a plurality of reactive radicals;  
       providing inside said process chamber a body including a recess for receiving said substrate, said recess having a nadir surface and a side surface extending from said nadir surface to an opening of said recess;  
       positioning said substrate in said recess of said body with said entire first opposed major surface of said substrate contacting said nadir surface of said recess and with said peripheral surface spaced from said side surface of said recess;  
       forming a flow of said reactive radicals directed toward said substrate; and  
       maintaining said flow for a sufficient amount of time to remove film present on said peripheral surface.  
     
     
       2. The method as recited in  claim 1  wherein said step of forming a flow includes forming a flow of reactive radicals that extends transversely to said first and second opposed major surfaces. 
     
     
       3. The method as recited in  claim 1  wherein said flow of reactive radicals is comprised of atoms associated with a reactive gas, with said reactive gas being selected from a group consisting of NF 3 , F 2 , diluted CF 4 , C 2 F 6 , C 3 F 8 , SF 6 , and ClF 3 . 
     
     
       4. The method as recited in  claim 1  wherein shielding said first surface from said flow includes positioning said substrate in the recess such that the peripheral surface is surrounded by said body and said body is spaced apart from said peripheral surface. 
     
     
       5. The method as recited in  claim 4  wherein said body is formed from aluminum nitride. 
     
     
       6. The method as recited in  claim 1  wherein said film is a dielectric film. 
     
     
       7. The method as recited in  claim 1  wherein said process chamber is pressurized to a pressure in the range of 0.5 to 3.0 Torr, inclusive. 
     
     
       8. The method as recited in  claim 1  wherein forming said plasma includes exciting a process gas with an RF component having a power in the range of 1 to 3 kilowatts. 
     
     
       9. The method as recited in  claim 1  wherein the flow of said reactive radicals is directed toward said second opposed major surface of said substrate. 
     
     
       10. The method as recited in  claim 1  wherein said peripheral surface of said substrate is spaced from said side surface of said recess by a distance of 5 to 30 mils, inclusive. 
     
     
       11. A method of removing film from a substrate of the type having first and second opposed major surfaces and a peripheral surface positioned therebetween, with said film being present on said first major opposed surface and said peripheral surface, with said substrate being disposed in a process chamber, said method comprising: 
       forming a plasma remotely with respect to said process chamber, said plasma including a plurality of reactive radicals;  
       providing inside said process chamber a body including a recess for receiving said substrate, said recess having a nadir surface and a side surface extending from said nadir surface to an opening of said recess;  
       positioning said substrate in said recess of said body with said entire first opposed major surface of said substrate contacting said nadir surface of said recess and with said peripheral surface spaced from said side surface of said recess;  
       forming a flow of said reactive radicals directed toward said substrate, avid said reactive radicals comprising atoms associated with a reactive gas, with said reactive gas being selected from a group consisting of NF 3 , F 2 , diluted CF 4 , C 2 F 6 , C 3 F 8 , SF 6 , and ClF 3 ; and  
       maintaining said flow for a sufficient amount of time to remove film present on said peripheral surface.  
     
     
       12. The method as recited in  claim 11  wherein said body is formed from aluminum nitride. 
     
     
       13. The method as recited in  claim 10  wherein said process chamber is pressurized to a pressure in the range of 0.5 to 3.0 Torr, inclusive. 
     
     
       14. The method as recited in  claim 10  wherein forming said plasma includes exciting a process gas with an RF component having a power in the range of 1 to 3 kilowatts. 
     
     
       15. The method as recited in  claim 11  wherein said film is a dielectric film. 
     
     
       16. The method as recited in  claim 11  wherein the flow of said reactive radicals is directed toward said second opposed major surface of said substrate. 
     
     
       17. The method as recited in  claim 11  wherein said peripheral spice of said substrate is spaced from said side surface of said recess by a distance of 5 to 30 mils, inclusive. 
     
     
       18. The method as recited in  claim 11  wherein the flow of said reactive radicals is oriented transversely to said first and second opposed major surfaces. 
     
     
       19. A method of removing film from a substrate of the type having first and second opposed major surfaces and a peripheral surface positioned therebetween, with said film being present on said first opposed major surface and said peripheral surface, with said substrate being disposed in a process chamber, said method comprising: 
       forming a plasma remotely with respect to said process chamber, said plasma including a plurality of reactive radicals;  
       forming a flow of said reactive radicals directed toward said substrate;  
       shielding said first opposed major surface from said flow by positioning said substrate in a recess of a body, said recess having a nadir surface, said substrate positioned in the recess such that the first opposed major surface is facing the nadir surface; and  
       maintaining said flow for a sufficient amount of time to remove film present on said peripheral surface,  
       wherein shielding said fist surface from said flow includes positioning said substrate in the recess such that the peripheral surface is surrounded by said body and said body is spaced apart from said peripheral surface,  
       wherein said body is spaced apart from said peripheral surface a distance in the range of 5 to 30 mils, inclusive.  
     
     
       20. A method of removing film from a substrate of the type having first and second opposed major surfaces and a peripheral surface positioned therebetween, with said film being present on said first major opposed surface and said peripheral surface, with said substrate being disposed in a process chamber, said method comprising: 
       forming a plasma remotely with respect to said process chamber, said plasma including a plurality of reactive radicals;  
       forming a flow of said reactive radicals directed toward said substrate, with said reactive radicals comprising atoms associated with a reactive gas, with said reactive gas being selected from a group consisting of NF 3 , F 2 , diluted CF 4 , C 2 F 6 , C 3 F 8 , SF 6 , and ClF 3 ;  
       shielding said first opposed major surface from said flow by positioning said substrate in a recess of a body, said recess having a nadir surface, said substrate positioned in the recess such that the first opposed major surface is facing the nadir surface, said peripheral surface is surrounded by said body, and said body is spaced apart from said peripheral surface; and  
       maintaining said flow for a sufficient amount of time to remove film present on said peripheral surface,  
       wherein said body is spaced apart from said peripheral surface a distance in the range of 5 to 30 mils, inclusive.